High temperature steam electrolyzing device

ABSTRACT

A high temperature steam electrolyzing device has: an electrolyzing cell section that includes a hydrogen electrode and an oxygen electrode arranged at mutually opposite sides of a solid oxide electrolyte operating as intermediate layer and electrolyzes steam to generate hydrogen; fixing flanges for fixing end sections of the solid oxide electrolyte of the electrolyzing cell section; a unit support member for supporting the fixing flanges; fitting flanges arranged at mutually opposite surfaces of the fixing flanges and the unit support member; gaskets made of metal or a mineral-based material and interposed between the fixing flanges and the fitting flanges and between the unit support member and the fitting flanges; and fastening members for separably fastening the fitting flanges.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is based upon and claims the benefits of priority from the prior Japanese Patent Applications No. 2007-158231, filed in the Japanese Patent Office on Jun. 15, 2007, the entire content of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention relates to a high temperature steam electrolyzing device for generating hydrogen by electrolyzing high temperature steam, utilizing waste heat from a nuclear reactor or the like.

A technique of obtaining hydrogen gas and oxygen gas by electrolyzing high temperature steam is known as high temperature steam electrolyzing method of this type. The principle of operation thereof is to utilize the reverse reaction of a solid oxide fuel cell (SOFC). Now, a planar high temperature steam electrolyzing cell will be described below as an example.

With the high temperature steam electrolyzing method, generally an electrochemical cell having a hydrogen electrode and an oxygen electrode with an intermediate layer of a solid oxide electrolyte is employed. Refined hydrogen is produced from the hydrogen electrode side and refined oxygen is produced from the oxygen electrode side. The hydrogen electrode side atmosphere contains steam and hydrogen that become fuel as principal ingredients, whereas the oxygen electrode side atmosphere contains nitrogen and oxygen as principal ingredients when supplied gas is air but contains oxygen as principal ingredient when supplied gas is oxygen. Therefore, a gas-sealing structure is indispensably required to separate the hydrogen electrode side atmosphere and the oxygen electrode side atmosphere.

A technique relating to a solid electrolyte type electrolyzing cell where gas is sealed by means of a sealing member is known from, for example, Japanese Patent Application Laid-Open Publication No. 06-275302, the entire contend of which is incorporated herein by reference, with regard to such a gas-sealing structure. A solid electrolyte type electrolyzing cell where gas is sealed will be described later by referring to FIG. 17.

The solid electrolyte type electrolyzing cell shown in FIG. 17 is roughly formed by a fuel electrode 1, a solid electrolyte 2 and an air electrode 3. They are pinched by an interconnector 5 by way of a collector plate 6 and a current collector 7 at the side of the fuel electrode 1 and an La type oxide ceramics 4 at the side of the air electrode 3.

The solid electrolyte 2 operates as support for the electrochemical cell and arranged at the ends thereof in a manifold 8 by way of sealing members 9.

A sealing structure of arranging a plurality of recesses at the ends of interconnectors above and below an electrolyte and filling the recesses with sealing members is known from, for example, Japanese Patent Application Laid-Open Publication No. 10-168590, the entire contend of which is incorporated herein by reference.

A structure of arranging recesses in a manifold and an electrolyte and inserting metal-made inserts into the recesses to improve the gas-sealing effect by utilizing the difference of thermal expansion is proposed in, for example, Japanese Patent Application Laid-Open Publication No. 09-002880 (the contents of which being incorporated herein by reference).

Effective usage including changing and repairing the electrolyzing cell in long time operations is not considered for the above-described known high temperature steam electrolyzing devices.

For example, the high temperature steam electrolyzing device shown in FIG. 17 has a structure where the sealing members 9 directly bears the loads and the vibrations of the electric collector plate 6, the current collector 7 and the interconnector 5 arranged above and below the solid electrolyte 2. For this reason, the sealing members 9 can lack long term reliability from the viewpoint of sealing effect and strength. Additionally, since the sealing members 9 operate as adhesive, the sealing members 9 need to be removed when the electrolyzing cell needs to be changed or repaired, and therefore maintenance is time consuming.

An electrochemical cell where a hydrogen electrode and an oxygen electrode are arranged with a solid oxide electrolyte as intermediate layer is employed with the above-described known high temperature steam electrolyzing devices. Hydrogen is produced from the hydrogen electrode side and oxygen is produced from the oxygen electrode side. Therefore, a gas-sealing structure is indispensably required to separate the hydrogen electrode side atmosphere and the oxygen electrode side atmosphere. This gas-sealing structure is a structure that adheres and connects the ends of the cell with use of glass, metal or the like.

When an electrochemical cell is used alone, the ends of the cell can be gas-sealed relatively easily. However, when such cells are stacked and employed as an assembly, there is a problem that the reliability of gas-sealing falls particularly at the ends of the cells.

There is also a problem that the long term reliability of the adhesive such as glass falls in terms of sealing effect and strength in a high-temperature range.

There is also a problem that the gas-sealing sections provide contact areas of the electrochemical cell and the interconnector and the cell support structure and hence the support strength and the durability thereof need to be maintained for a long time.

Furthermore, when a large capacity hydrogen manufacturing apparatus is formed as an assembly by stacking a plurality of solid electrolyte type electrolyzing cells with the known arrangement and only part of the plurality of solid electrolyte type electrolyzing cells fails or ends the service life, those solid electrolyte type electrolyzing cells cannot be changed or taken out individually without difficulty. Therefore, there is a problem that the maintainability of changing or repairing such solid electrolyte type electrolyzing cells individually needs to be improved.

BRIEF SUMMARY OF THE INVENTION

The present invention has been invented in order to solve the problem described above. An objective of the invention is to provide a high temperature steam electrolyzing device that increases reliability of gas sealing, makes the device more compact, and makes the changing and repairing works easier.

In order to achieve the objectives, according to the present invention, there is presented a high temperature steam electrolyzing device comprising: an electrolyzing cell section that includes a hydrogen electrode and an oxygen electrode arranged at mutually opposite sides of a solid oxide electrolyte operating as intermediate layer and electrolyzes steam to generate hydrogen; fixing flanges for fixing end sections of the solid oxide electrolyte of the electrolyzing cell section; a unit support member for supporting the fixing flanges; fitting flanges arranged at mutually opposite surfaces of the fixing flanges and the unit support member; gaskets made of metal or a mineral-based material and interposed between the fixing flanges and the fitting flanges and between the unit support member and the fitting flanges; and fastening members for separably fastening the fitting flanges.

In order to achieve the objectives, according to the present invention, there is also presented a high temperature steam electrolyzing device comprising: an electrolyzing cell section that includes an oxygen electrode and a hydrogen electrode made of a porous material and having a conical profile with an upwardly increasing horizontal cross-sectional area, the oxygen electrode and the hydrogen electrode being arranged respectively above and below a solid oxide electrolyte extending in a horizontal direction and operating as an intermediate layer and electrolyzes steam to generate hydrogen; a conical metal-made fixing ring that has an inner surface with an upwardly increasing horizontal cross-sectional area for receiving the conical hydrogen electrode inserted therein; a unit support member for supporting the fixing ring; fitting flanges arranged at mutually opposite surfaces of the fixing ring and the unit support member; gaskets made of metal or a mineral-based material and interposed between the fixing ring and the unit support member; and fastening members for separably fastening the fitting flanges.

In order to achieve the objectives, according to the present invention, there is also presented a high temperature steam electrolyzing device comprising: an electrolyzing cell section that includes a hydrogen electrode and an oxygen electrode made of a porous material and having a conical profile with an upwardly increasing horizontal cross-sectional area, the oxygen electrode and the hydrogen electrode being arranged respectively above and below a solid oxide electrolyte extending in a horizontal direction and operating as an intermediate layer and electrolyzes steam to generate hydrogen; a conical metal-made fixing ring that has an inner surface with an upwardly increasing horizontal cross-sectional area for receiving the conical electrode inserted therein; a unit support member for supporting the fixing ring; fitting flanges arranged at mutually opposite surfaces of the fixing ring and the unit support member; gaskets made of metal or a mineral-based material and interposed between the fixing ring and the unit support member; and fastening members for separably fastening the fitting flanges.

In order to achieve the objectives, according to the present invention, there is also presented a high temperature steam electrolyzing device comprising: an electrolyzing cell section that includes a hydrogen electrode and an oxygen electrode arranged at mutually opposite sides of a solid oxide electrolyte operating as intermediate layer and electrolyzes steam to generate hydrogen; a porous metal-made support member for supporting lower surface of the hydrogen electrode of the electrolyzing cell section; a metal-made fixing ring arranged outside the porous metal-made support member and connected to end surface of the porous metal-made support member by way of a weld section; and a unit support member for support end section of the metal-made fixing ring.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present invention will become apparent from the discussion hereinbelow of specific, illustrative embodiments thereof presented in conjunction with the accompanying drawings, in which:

FIG. 1 is a longitudinal cross-sectional view of the first embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the fitting flanges and the gaskets of the electrolyzing cell sections;

FIG. 2 is an enlarged longitudinal cross-sectional view of part “II” of the fitting flanges and the gaskets of FIG. 1;

FIG. 3 is a longitudinal cross-sectional view of the second embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the fitting flanges and the gaskets of the electrolyzing cell sections;

FIG. 4 is an enlarged longitudinal cross-sectional view of part “IV” of the fitting flanges and the gaskets of FIG. 3;

FIG. 5 is a plan view of the high temperature steam electrolyzing device of FIG. 3, showing the arrangement of the fitting flanges and the gaskets of the electrolyzing cell sections;

FIG. 6 is a longitudinal cross-sectional view of the third embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the fitting flanges and the gaskets of the electrolyzing cell sections;

FIG. 7 is an enlarged longitudinal cross-sectional view of part “VII” of the fitting flanges and the gaskets of FIG. 6;

FIG. 8 is a longitudinal cross-sectional view of the fourth embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the electrolyzing cell sections;

FIG. 9 is an enlarged longitudinal cross-sectional view of part “IX” of the electrolyzing cell sections of FIG. 8;

FIG. 10 is a longitudinal cross-sectional view of the fifth embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the fitting flanges and the gaskets of the electrolyzing cell sections;

FIG. 11 is an enlarged longitudinal cross-sectional view of part “XI” of the fitting flanges and the gaskets of FIG. 10;

FIG. 12 is a longitudinal cross-sectional view of the sixth embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the electrolyzing cell sections;

FIG. 13 is an enlarged longitudinal cross-sectional view of part “XIII” of the electrolyzing cell sections of FIG. 12;

FIG. 14 is an enlarged longitudinal cross-sectional view of the seventh embodiment of a high temperature steam electrolyzing device according to the present invention, showing a principal part of the electrolyzing cell;

FIG. 15 is an enlarged longitudinal cross-sectional view of the eighth embodiment of a high temperature steam electrolyzing device according to the present invention, showing a principal part of the electrolyzing cell;

FIG. 16 is an enlarged longitudinal cross-sectional view of the ninth embodiment of a high temperature steam electrolyzing device according to the present invention, showing a principal part of the electrolyzing cell; and

FIG. 17 is a longitudinal cross-sectional view of a known solid electrolyte type electrolyzing cell sections.

DETAILED DESCRIPTION OF THE INVENTION

Now, embodiments of high temperature steam electrolyzing cell according to the present invention will be described below by referring to the drawings. The same or similar parts are denoted by the same reference symbols and will not be described repeatedly.

First Embodiment

FIG. 1 is a longitudinal cross-sectional view of the first embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the fitting flanges 104 and the gaskets 107 of the electrolyzing cell sections 120, and FIG. 2 is an enlarged longitudinal cross-sectional view of part “II” of the fitting flanges 104 and the gaskets 107 of FIG. 1.

Firstly, the arrangement of the high temperature steam electrolyzing device will be described by referring to FIG. 1.

As shown in FIG. 1, the high temperature steam electrolyzing device is formed mainly by electrolyzing cell sections 120 arranged between two separation plates 112 by way of interconnectors 109 for electric connection, cell sealing sections 121 for sealing the electrolyzing cell sections 120, and unit support members 110 for supporting the cell sealing sections 121. The electrolyzing cell sections 120 have hydrogen electrodes 102 and oxygen electrodes 103 arranged at the respective opposite sides of solid oxide electrolytes 101 operating as intermediate layers.

As shown in FIG. 2, the cell sealing sections 121 have fixing flanges 130, metal-made fitting flanges 104, metal-made bolts 105, metal-made nuts 106 and gaskets 107. Examples of preferable material of the gaskets 107 include metals such as ferrite-type stainless steel and minerals containing vermiculite or the like as principal ingredient. The solid oxide electrolytes 101 of the electrolyzing cell sections 120 are pinched from the opposite sides by the fixing flanges 130 by way of the gaskets 107. Two fixing flanges 130 are fastened by means of the bolts 105 and the nuts 106 that are fastening members by way of the gaskets 107. The opposite sides of the fixing flanges 130 and the unit support members 110 are pinched by the fitting flanges 104 by way of the gaskets 107. The two fitting flanges 104 are fastened by means of the bolts 105 and the nuts 106 that are fastening members by way of the gaskets 107. Thus, the solid oxide electrolytes 101 of the electrolyzing sell section 120 are fastened by the bolts 105 and the nuts 106 by way of the fitting flanges 104 and the gaskets 107 to form the high temperature steam electrolyzing device.

The solid oxide electrolytes 101 are disk-shaped, and the material, the size, the thickness and the manufacturing method thereof may be arbitrarily selected. The materials, the profiles, the sizes and the thicknesses of the hydrogen electrodes 102 and the oxygen electrodes 103 may also be arbitrarily selected and the method of application to the solid oxide electrolytes 101 may also be arbitrarily selected. A preferable example of material of the hydrogen electrodes 102 is a mixture of nickel and stabilized zirconia, while a preferable example of material of the oxygen electrode 103 is a lanthanum-cobalt based oxide. The materials, the numbers and the sizes of the bolts 105 and the nuts 106 are not subjected to any particular limits. The material of the fitting flanges 104 may be selected arbitrarily and the shape may also be selected arbitrarily from circular, rectangular and so on. The size of the gaskets 107 may be selected arbitrarily. They may be made of metal or a mineral-based material.

In this embodiment having the above-described arrangement, the solid oxide electrolytes 101 of the electrolyzing cell sections 120 are pinched from the opposite sides by the fixing flanges 130 by way of the gaskets 107 and the fixing flanges 130 and the unit support members 110 are pinched from the opposite sides by the fitting flanges 104 by way of the gaskets 107 and fastened by way of the gaskets 107 and by means of the bolts 105 and the nuts 106. Due to the gaskets 107, a hermetically sealed structure that can be gas-sealed can be formed at the boundaries of the electrolyzing cell sections 120, the fixing flanges 130 and the fitting flanges 104 and the boundaries of the fitting flanges 104 and the bolts 105 and the nuts 106.

The sealing effect can be improved by utilizing the difference of thermal expansion as a result of using metal or a mineral-based material as the material of the gaskets 107. In such a high temperature steam electrolyzing device, the electrolyzing cell sections 120 and the gaskets 107 have a structure that can be changed or repaired with ease simply by taking off the bolts 105 and the nuts 106. Additionally, the electrolyzing cell sections 120 are disk-shaped and the fixing flanges 130 are ring-shaped so that the ends of the fixing flanges 130 can be connected to the unit support members 110 by way of screw sections 204.

The above-described electrolyzing cell sections 120 are arranged so as to be brought into contact with the interconnectors 109 from above and from below of the electrolyzing cell sections 120 tor feed and collection of electricity. The upper and lower electrolyzing cell sections 120 are structurally isolated by way of separation plates 112. The interconnectors 109 are porous or have a corrugated shape and a gas diffusing property. They may be made of an arbitrarily selected material. The material of the separation plates 112 is an electro-conductive material and may have an arbitrarily selected shape.

With this embodiment, because the gaskets 107 are made of metal or a mineral-based material and employed as gas-sealing members, the electrolyzing cell sections 120 of a high temperature steam electrolyzing device can be formed so as to improve the gas-sealing reliability and changed or repaired with ease. Additionally, because the screw sections 204 are formed at the end facets of the fixing flanges 130, the solid oxide electrolytes 101 and the unit support members 110, a unit can be formed by assembling a plurality of electrolyzing cell sections 120 at the unit support members 110 so as to improve the gas-sealing effect and obtain a high temperature steam electrolyzing device that can be assembled and disassembled with ease.

Second Embodiment

FIG. 3 is a longitudinal cross-sectional view of the second embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the fitting flanges 104 and the gaskets 107 of the electrolyzing cell sections 120 a. FIG. 4 is an enlarged longitudinal cross-sectional view of part “IV” of the fitting flange 104 and a gasket 107 of FIG. 3. FIG. 5 is a plan view of the high temperature steam electrolyzing device of FIG. 3, showing the arrangement of the fitting flanges and the gaskets of the electrolyzing cell sections. The components similar to those of the first embodiment are denoted by the same reference symbols and will not be described repeatedly.

As shown in the drawings, the high temperature steam electrolyzing device is formed mainly by electrolyzing cell sections 120 a and unit support members 110 for supporting the electrolyzing cell sections 120 a. The electrolyzing cell sections 120 a have hydrogen electrodes 102 and oxygen electrodes 103 arranged at the respective opposite sides of solid oxide electrolytes 101 operating as intermediate layers.

As seen from FIGS. 3 and 5, the electrolyzing cell sections 120 a are arranged respectively at a plurality of apertures arranged in the form of a square lattice on a single unit support member 110 and rigidly secured by fitting flanges 104.

As shown in FIG. 4, unit support members 110 are arranged at the opposite sides of the electrolyzing cell sections 120 a. The unit support members 110 have hydrogen electrode feed layers 201 for feeding electricity to the hydrogen electrodes 102 of the electrolyzing cell sections 120 a, oxygen electrode collection layers 203 for collecting electricity from the oxygen electrodes 103, and insulation layers 202 for insulating the hydrogen electrode feed layers 201 and the oxygen electrode collection layers 203.

The electrolyzing cell sections 120 a and the unit support members 110 are sealed by cell sealing sections 121. At the cell sealing sections 121, the solid oxide electrolytes 101 of the electrolyzing cell sections 120 a are pinched from the opposite sides by the fitting flanges 104 by way of the gaskets 107 and additionally fastened by means of bolts 105 and nuts 106 that are fastening members by way of the gaskets 107. Additionally, the fitting flanges 104 and the hydrogen electrode feed layers 201 of the unit support members 110 are connected by way of weld sections 205. Furthermore, the fitting flanges 104 and the oxygen electrode collection layers 203 of the unit support members 110 are connected by way of the weld sections 205.

In this embodiment having the above-described arrangement, the gas-sealing effect is established for the hydrogen electrode side atmosphere and the oxygen electrode side atmosphere of the electrolyzing cell sections 120 a by way of the gaskets 107 and the weld sections 205. Additionally, each of the unit support members 110 is formed by three layers of a hydrogen electrode feed layer 201, an oxygen electrode collection layer 203 and an insulation layer 202 and operate for both feed and collection of electricity. Feed of electricity to the hydrogen electrode feed layers 201 and collection of electricity from the oxygen electrode collection layers 203 of the electrolyzing cell sections 120 a are structurally realized by way of the metal-made fitting flanges 104 and electro-conductive meshes 111. Gaskets 107 made of a mineral-based material are used at the connecting sections with the bolts 105 in order to establish insulation of the hydrogen electrodes 102 and the oxygen electrodes 103. The shape and the material of the electro-conductive meshes 111 may be arbitrarily selected.

With this embodiment, the gas-sealing reliability and the safety can be improved because the gaskets 107 are made of metal or a mineral-based material and employed as sealing members for the electrolyzing cell sections 120 a. Additionally, since the unit support members 110 operate for both feed and collection of electricity, the high temperature steam electrolyzing device can be further simplified and downsized.

Third Embodiment

FIG. 6 is a longitudinal cross-sectional view of the third embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the fitting flanges 104 and the gaskets 107 of the electrolyzing cell sections 102 b. FIG. 7 is an enlarged longitudinal cross-sectional view of part “VII” of a fitting flange 104 and a gasket 107 of FIG. 3. The components similar to those of the first embodiment are denoted by the same reference symbols and will not be described repeatedly.

As shown in the drawings, the high temperature steam electrolyzing device is formed mainly by electrolyzing cell sections 120 b and unit support members 110 for supporting the electrolyzing cell sections 120 b. The electrolyzing cell sections 120 b have hydrogen electrodes 102 and oxygen electrodes 103 arranged at the respective opposite sides of solid oxide electrolytes 101 operating as intermediate layers. Metal-made fixing rings 108 are interposed between the electrolyzing cell sections 120 b and the unit support members 110.

As shown in FIG. 7, the hydrogen electrodes 102 of the electrolyzing cell sections 120 b are plate-shaped and extend in a horizontal direction. They are made of a porous material and processed to show a conical profile such that the horizontal cross-sectional area thereof upwardly increases. The hydrogen electrodes 102 are embedded in the metal-made fixing rings 108 that are processed so as to make their inner surfaces upwardly expand and operate as electrode support members for the electrolyzing cell sections 120 b. The electrolyzing cell sections 120 b are formed to provide a gas-sealing effect as the solid oxide electrolytes 101 are applied from the bottom surface sides of the conical porous hydrogen electrodes 102 to the fixing rings 108.

The electrolyzing cell sections 120 b are disk-shaped and the fixing flanges 130 are ring-shaped. When an electrolyzing unit is formed by assembling a plurality of electrolyzing cell sections 120 b, screw sections 204 are formed between the end surfaces of the fixing rings 108 and the unit support members 110. The fixing rings 108 and the unit support members 110 are connected by way of the screw sections 204. The electrolyzing cell sections 120 b connected to the unit support members 110 by way of the screw sections 204 are pinched by the fitting flanges 104 by way of the gaskets 107 so as to structurally provide a gas-sealing effect.

Additionally, the upper and lower electrolyzing cell sections 120 b are isolated by feed support members 123. The feed support members 123 are formed by hydrogen electrode feed layers 201, oxygen electrode collection layers 203 and insulation layers 202 for electrically insulating the hydrogen electrode feed layers 201 and the oxygen electrode collection layers 203.

Feed of electricity to the hydrogen electrodes 102 of the electrolyzing cell sections 120 b is realized by the hydrogen electrode feed layers 201 of the feed support members 123 by way of the interconnectors 109. Collection of electricity from the oxygen electrodes 103 of the electrolyzing cell sections 120 b is realized by the oxygen electrode collection layers 203 of the feed support members 123 by way of the interconnectors 109.

The material, the porosity and the size of the porous hydrogen electrodes 102 may be arbitrarily selected and the manufacturing method may also be arbitrarily selected. The materials, the shapes, the sizes and the thicknesses of the solid oxide electrolytes 101 and the oxygen electrodes 103 may be arbitrarily selected and the application method may also be arbitrarily selected. The size, the thickness and the angle of inclination of the metal-made fixing rings 108 may be arbitrarily selected. The materials, the numbers and the sizes of the bolts 105 and the nuts 106 may be freely selected. The material of the fitting flanges 104 may also be arbitrarily selected. The gaskets 107 are made of metal or a mineral-based material. The interconnectors 109 have a shape of a porous member or a corrugated shape and a gas diffusing property. They may be made of an arbitrarily selected material.

The above description also applies when the oxygen electrodes 103 are employed as porous electrode support members.

With this embodiment, as the porous hydrogen electrodes 102 that are processed so as to show a conical profile as electrode support members are embedded in the fixing rings 108 having a conical inner surface, a high temperature steam electrolyzing device supporting the electrolyzing cell sections 120 b can be formed without using any adhesive. Additionally, a gas-sealing effect can be realized without using an adhesive such as glass by applying the solid oxide electrolytes 101 also to the fixing rings 108. Furthermore, screw sections 204 are formed between the end surfaces of the fixing rings 108 and the unit support members 110 when a plurality of electrolyzing cell sections 120 b are assembled. A high temperature steam electrolyzing device which does not require an adhesive such as glass and whose electrolyzing cell sections 120 b and so on can be changed or repaired with ease can be obtained by connecting by way of the screw sections 204.

Forth Embodiment

FIG. 8 is a longitudinal cross-sectional view of the fourth embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the electrolyzing cell sections 120 c. FIG. 9 is an enlarged longitudinal cross-sectional view of part “IX” of an electrolyzing cell section 120 c of FIG. 8. The components similar to those of the first embodiment are denoted by the same reference symbols and will not be described repeatedly.

As shown in FIG. 8, the high temperature steam electrolyzing device is formed mainly by electrolyzing cell sections 120 c and unit support members 110 for supporting the electrolyzing cell sections 120 c. The electrolyzing cell sections 120 c have hydrogen electrodes 102 and oxygen electrodes 103 arranged at the respective opposite sides of solid oxide electrolytes 101 operating as intermediate layers.

As shown in FIG. 9, the unit support members 110 are arranged at the opposite sides of the electrolyzing cell sections 120 c. The unit support members 110 have hydrogen electrode feed layers 201 for feeding electricity to the hydrogen electrodes 102 of the electrolyzing cell sections 120 c, oxygen electrode collection layers 203 for collecting electricity from the oxygen electrodes 103 and insulation layers 202 for insulating the hydrogen electrode feed layers 201 and the oxygen electrode collection layers 203.

The hydrogen electrodes 102 are made of a porous material and processed to show a conical profile such that the horizontal cross-sectional areas thereof upwardly increase. The porous hydrogen electrodes 102 are embedded in the metal-made fixing rings 108 that are processed so as to have through holes whose horizontal cross-sectional areas upwardly increase.

In this embodiment having the above-described arrangement, the electrolyzing cell sections 120 c are supported by the porous hydrogen electrodes 102 and embedded in the through holes of the metal-made fixing rings 108 and the solid oxide electrolytes 101 are applied to the fixing rings 108.

Additionally, the fixing rings 108 and the hydrogen electrode feed layers 201 of the unit support members 110 are connected by way of weld sections 205. The oxygen electrode collection layers 203 are structurally held in contact with the oxygen electrodes 103 by way of electro-conductive meshes 111 with interposition of the insulation layers 202 of the unit support members 110. The upper and lower electrolyzing cell sections 120 c are isolated by way of separation plates 112. The material of the separation plates 112 is an electro-conductive material and may have an arbitrarily selected shape.

An arrangement similar to the above-described one may be adopted when the porous oxygen electrodes 103 operate as electrode support members.

With this embodiment, the porous hydrogen electrodes 102 that are processed so as to show a conical profile as electrode support members are embedded in the fixing rings 108 having a conical inner surface. Thus, a high temperature steam electrolyzing device supporting the electrolyzing cell sections 120 c can be formed without using any adhesive. Additionally, since the unit support members 110 operate for both feed and collection of electricity, the high temperature steam electrolyzing device can be further simplified and downsized.

Fifth Embodiment

FIG. 10 is a longitudinal cross-sectional view of the fifth embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the fitting flanges 104 and the gaskets 107 of the electrolyzing cell sections 120 d. FIG. 11 is an enlarged longitudinal cross-sectional view of part “XI” of a fitting flange 104 and a gasket 107 of FIG. 10. The components similar to those of the first embodiment are denoted by the same reference symbols and will not be described repeatedly.

As shown in the drawings, the high temperature steam electrolyzing device is formed mainly by electrolyzing cell sections 120 d and unit support members 110 for supporting the electrolyzing cell sections 120 d. The electrolyzing cell sections 120 d have hydrogen electrodes 102 of a porous material and oxygen electrodes 103 arranged at the respective opposite sides of solid oxide electrolytes 101 operating as intermediate layers. Porous metal-made support members 113 are arranged on the lower surfaces of the hydrogen electrodes 102. The upper and lower electrolyzing cell sections 120 d are separated by separation plates 112.

Metal-made fixing rings 108 are interposed between the porous metal-made support members 113 of the electrolyzing cell sections 120 d and the unit support members 110. The metal-made fixing rings 108 and the porous metal-made support members 113 are connected by way of weld sections 205.

The electrolyzing cell sections 120 d are disk-shaped and the fixing rings 108 are ring-shaped. As screw sections 204 are formed, the metal-made fixing rings 108 and the unit support members 110 are connected by way of the screw sections 204.

Metal-made fitting flanges 104 are arranged at the opposite sides of the fixing rings 108 and the unit support members 110 that are connected interleaving gaskets 107 that are made of metal or a mineral-based material. The metal-made fitting flanges 104 are fastened tight by means of bolts 105 and nuts 106 that are a sort of fastening members, by way of the gaskets 107 that are made of metal or a mineral-based material.

In this embodiment having the above-described arrangement, the electrolyzing cell sections 120 d are supported by the porous metal-made support members 113. The hydrogen electrodes 102, the solid oxide electrolytes 101 and the oxygen electrodes 103 are sequentially arranged on the upper surfaces of the porous metal-made support members 113. In the electrolyzing cell sections 120 d, the porous metal-made support members 113 and the metal-made fixing rings 108 are connected by way of the weld sections 205 and the end surfaces of the metal-made fixing rings 108 and the unit support members 110 are connected by way of the screw sections 204. The generated gas can be structurally hermetically sealed by pinching by means of the fitting flanges 104 by way of the gaskets 107. Feed of electricity to the hydrogen electrodes 102 and collection of electricity from the oxygen electrodes 103 are realized by bringing the interconnectors 109 arranged above and below the hydrogen electrodes 102 d and the oxygen electrodes 103 into contact. The upper and lower electrolyzing cell sections 120 are structurally isolated by way of separation plates 112.

The interconnectors 109 are formed in a porous member or a corrugated shape, and have a gas diffusing property. They may be made of an arbitrarily selected material. The shape and the material of the fitting flanges 104 may be arbitrarily selected. The material of the separation plates 112 is an electro-conductive material and may have an arbitrarily selected shape. The gaskets 107 are made of metal or a mineral-based material.

With this embodiment, the porous metal-made support members 113 are employed as the electrode support members of the electrolyzing cell sections 120 d, and hence the durability of the electrode support members can be improved. Additionally, the gaskets 107 that are made of metal or a mineral-based material are employed as gas-sealing members, and hence, the reliability of gas-sealing is improved, and the electrochemical cells can be changed or repaired with ease. Furthermore, since the fitting flanges 104 are fastened tight by the bolts 105 and the nuts 106, gas-sealing of the units formed by assembling a plurality of electrolyzing cell sections 120 d onto the unit support members 110 can be realized. In addition, a unit structure of electrochemical cells that can be fitted and taken out with ease can be realized.

Sixth Embodiment

FIG. 12 is a longitudinal cross-sectional view of the sixth embodiment of a high temperature steam electrolyzing device according to the present invention, showing the arrangement of the electrolyzing cell sections 120 e. FIG. 13 is an enlarged longitudinal cross-sectional view of part “XIII” of an electrolyzing cell section 120 e of FIG. 12. The components similar to those of the fifth embodiment are denoted by the same reference symbols and will not be described repeatedly.

As shown in FIG. 12, the high temperature steam electrolyzing device is formed mainly by electrolyzing cell sections 120 e, and unit support members 110 for supporting the electrolyzing cell sections 120 e. The electrolyzing cell sections 120 e have hydrogen electrodes 102 and oxygen electrodes 103, each made of a porous material arranged at the respective opposite sides of solid oxide electrolytes 101 operating as intermediate layers. Porous metal-made support members 113 are arranged on the lower surfaces of the hydrogen electrodes 102.

As shown in FIG. 13, the fixing rings 108 that are components of the electrolyzing cell sections 120 e are not provided with screw sections 204 as shown in FIG. 10. In the electrolyzing cell sections 120 e, the porous metal-made support members 113 and the metal-made fixing rings 108 are connected by way of weld sections 205, and the end surfaces of the metal-made fixing rings 108 and the unit support members 110 are connected by way of the weld sections 205.

The unit support members 110 have hydrogen electrode feed layers 201 for feeding electricity to the hydrogen electrodes 102 of the electrolyzing cell sections 120 e, oxygen electrode collection layers 203 for collecting electricity from the oxygen electrodes 103 by way of electro-conductive meshes 111, and insulation layers 202 for insulating the hydrogen electrode feed layers 201 and the oxygen electrode collection layers 203.

In this embodiment having the above-described arrangement, the electrolyzing cell sections 120 e that are supported by the porous metal-made support members 113 are connected in the metal-made fixing rings 108 by way of the weld sections 205, and the solid oxide electrolytes 101 are applied to the fixing rings 108. The fixing rings 108 and the hydrogen electrode feed layers 201 that operate as unit support members 110 are connected by way of the weld sections 205. Additionally, the oxygen electrode collection layers 203 are structurally held in contact with the oxygen electrodes 103 by way of the electro-conductive meshes 111 with interposition of the insulation layers 202.

The above description also applies when the porous oxygen electrodes 103 are employed as support members.

With this embodiment, the electrolyzing cell sections 120 e can be formed without using any adhesive by connecting the porous metal-made support members 113 that are processed as electrode support members by way of the weld sections 205 after embedded in the through holes of the metal-made fixing rings 108 whose inner surfaces are processed. Additionally, since the unit support members 110 also operate as feed members and collection members, the high temperature steam electrolyzing device can further be simplified and downsized.

Furthermore, the durability of the electrode support members can be improved as a result of employing the porous metal-made support members 113 as electrode support members for the hydrogen electrodes 102 of the electrolyzing cell sections 120 e. Additionally, the gas-sealing reliability can be improved and the electrochemical cells can be changed or repaired with ease, because the gaskets 107 that are made of metal or a mineral-based material are employed as sealing members. Still additionally, since the unit support members 110 also operate as feed members and collection members, the high temperature steam electrolyzing device can further be simplified and downsized.

Seventh Embodiment

FIG. 14 is an enlarged longitudinal cross-sectional view of the seventh embodiment of a high temperature steam electrolyzing device according to the present invention, showing a principal part of an electrolyzing cell section thereof which corresponds to FIG. 2 of the first embodiment (part “II” of FIG. 1). This embodiment is a modification of the first embodiment and the components similar to those of the first embodiment are denoted by the same reference symbols and will not be described repeatedly.

In this embodiment, annular gaps 114 are provided between the apertures of the unit support members 110 and the outer end sections of the fixing flanges 130 and no screw is formed between them. Like the first embodiment, two fixing flanges 130 are fitted so as to pinch a solid oxide electrolyte 101 at opposite surfaces near an end and the fixing flanges 130 and a unit support member 110 are pinched by two fitting flanges 104 interleaving gaskets 107 and fastened tight by means of bolts 105 and nuts 106.

Like the first embodiment, the gas-sealing reliability of this embodiment is improved as a result of using the gaskets 107 that are made of metal or a mineral-based material for the gas-sealing structure, and additionally changing or repairing works can be conducted with ease.

Additionally, with this embodiment, since gaps 114 are provided between the apertures of the unit support members 110 and the outer end sections of the fixing flanges 130, the difference of thermal expansion between the apertures of the unit support members 110 and the fixing flanges 130 and the fitting flanges 104 can be absorbed. In other words, the electrolyzing cells operate exothermically or endothermically depending on the operating condition of the electrolyzing cells so that temperature differences arise around the electrolyzing cells to produce strain due to thermal expansion. However, in this embodiment, destruction of the device can be avoided that can be caused by strain due to thermal expansion, and soundness of the device is maintained.

Eighth Embodiment

FIG. 15 is an enlarged longitudinal cross-sectional view of the eighth embodiment of a high temperature steam electrolyzing device according to the present invention, showing a principal part of an electrolyzing cell section thereof which corresponds to FIG. 7 of the third embodiment (part “VII” of FIG. 6). This embodiment is a modification of the third embodiment and the components similar to those of the third embodiment are denoted by the same reference symbols and will not be described repeatedly.

In this embodiment, annular gaps 115 are provided between the apertures of the unit support members 110 and the outer end sections of the fixing rings 108 and no screw is formed between them. Like the third embodiment, a fixing ring 108 and a unit support member 110 are pinched by two fitting flanges 104 interleaving gaskets 107 and fastened tight by means of bolts 105 and nuts 106.

Like the third embodiment, the gas-sealing reliability of this embodiment is improved as a result of using the gaskets 107 that are made of metal or a mineral-based material for the gas sealing structure. Additionally, changing or repairing works can be conducted with ease.

Additionally, with this embodiment, since gaps 115 are provided between the apertures of the unit support members 110 and the outer end sections of the fixing rings 108, the difference of thermal expansion between the apertures of the unit support members 110 and the fixing rings 108 and the fitting flanges 104 can be absorbed. As a result, this embodiment provides advantages similar to those of the seventh embodiment.

Ninth Embodiment

FIG. 16 is an enlarged longitudinal cross-sectional view of the eighth embodiment of a high temperature steam electrolyzing device according to the present invention, showing a principal part of an electrolyzing cell section thereof which corresponds to FIG. 11 of the fifth embodiment (part “XI” of FIG. 10). This embodiment is a modification of the fifth embodiment and the components similar to those of the fifth embodiment are denoted by the same reference symbols and will not be described repeatedly.

In this embodiment, annular gaps 115 are provided between the apertures of the unit support members 110 and the outer end sections of the fixing rings 108 and no screw is formed between them. Like the fifth embodiment, a fixing ring 108 and a unit support member 110 are pinched by two fitting flanges 104 interleaving gaskets 107 and fastened tight by means of bolts 105 and nuts 106.

Like the fifth embodiment, the gas-sealing reliability of this embodiment is improved as a result of using the gaskets 107 that are made of metal or a mineral-based material for the gas sealing structure. Additionally, changing or repairing works can be conducted with ease.

Additionally, with this embodiment, since gaps 115 are provided between the apertures of the unit support members 110 and the outer end sections of the fixing rings 108, the difference of thermal expansion between the apertures of the unit support members 110 and the fixing rings 108 and the fitting flanges 104 can be absorbed. As a result, this embodiment provides advantages similar to those of the seventh embodiment and the eighth embodiment.

Other Embodiments

The present invention is described above by way of embodiments. However, the present invention is by no means limited to the above-described embodiments, the arrangements of which may be combined and modified in various different ways without departing from the spirit of the present invention.

For example, while a plurality of electrolyzing cell sections, each extending in a horizontal direction, are laid in a vertical direction to form a multilayer structure in the first, third and fifth embodiments, those embodiments may be so modified to show a structure where a plurality of electrolyzing cell sections are arranged in a horizontal direction like the second embodiment (FIG. 3, FIG. 5) and so on. 

1. A high temperature steam electrolyzing device comprising: an electrolyzing cell section that includes a hydrogen electrode and an oxygen electrode arranged at mutually opposite sides of a solid oxide electrolyte operating as intermediate layer and electrolyzes steam to generate hydrogen; fixing flanges for fixing end sections of the solid oxide electrolyte of the electrolyzing cell section; a unit support member for supporting the fixing flanges; fitting flanges arranged at mutually opposite surfaces of the fixing flanges and the unit support member; gaskets made of metal or a mineral-based material and interposed between the fixing flanges and the fitting flanges and between the unit support member and the fitting flanges; and fastening members for separably fastening the fitting flanges.
 2. The high temperature steam electrolyzing device according to claim 1, wherein the solid oxide electrolyte is disk-shaped, the fixing flanges for fixing the end sections of the solid oxide electrolyte are ring-shaped, and the fixing flanges and the unit support member are connected by way of screw sections.
 3. The high temperature steam electrolyzing device according to claim 1, wherein the unit support member has a hydrogen electrode feed layer for feeding electricity to the hydrogen electrode of the electrolyzing cell section, an oxygen electrode collection layer for collecting electricity from the oxygen electrode and an insulation layer for insulating the hydrogen electrode feed layer and the oxygen electrode collection layer, and the fixing flanges for fixing the end sections of the solid oxide electrolyte and the unit support member are connected by way of a weld section.
 4. The high temperature steam electrolyzing device according to claim 1, wherein the fixing flanges for fixing the end sections of the solid oxide electrolyte and the unit support member are disposed face to face by way of an annular gap.
 5. A high temperature steam electrolyzing device comprising: an electrolyzing cell section that includes an oxygen electrode and a hydrogen electrode made of a porous material and having a conical profile with an upwardly increasing horizontal cross-sectional area, the oxygen electrode and the hydrogen electrode being arranged respectively above and below a solid oxide electrolyte extending in a horizontal direction and operating as an intermediate layer and electrolyzes steam to generate hydrogen; a conical metal-made fixing ring that has an inner surface with an upwardly increasing horizontal cross-sectional area for receiving the conical hydrogen electrode inserted therein; a unit support member for supporting the fixing ring; fitting flanges arranged at mutually opposite surfaces of the fixing ring and the unit support member; gaskets made of metal or a mineral-based material and interposed between the fixing ring and the unit support member; and fastening members for separably fastening the fitting flanges.
 6. The high temperature steam electrolyzing device according to claim 5, wherein the hydrogen electrode is disk-shaped and the fixing ring for receiving the solid oxide electrolyte inserted therein and the unit support member are connected by way of screw sections.
 7. The high temperature steam electrolyzing device according to claim 5, wherein the unit support member has a hydrogen electrode feed layer for feeding electricity to the hydrogen electrode of the electrolyzing cell section, an oxygen electrode collection layer for collecting electricity from the oxygen electrode and an insulation layer for insulating the hydrogen electrode feed layer and the oxygen electrode collection layer, and the fixing ring for receiving the hydrogen electrode inserted therein and the hydrogen electrode feed layer of the unit support member are connected by way of a weld section.
 8. The high temperature steam electrolyzing device according to claim 5, wherein the fixing ring for receiving the hydrogen electrode inserted therein and the unit support member are disposed face to face by way of an annular gap.
 9. A high temperature steam electrolyzing device comprising: an electrolyzing cell section that includes a hydrogen electrode and an oxygen electrode made of a porous material and having a conical profile with an upwardly increasing horizontal cross-sectional area, the oxygen electrode and the hydrogen electrode being arranged respectively above and below a solid oxide electrolyte extending in a horizontal direction and operating as an intermediate layer and electrolyzes steam to generate hydrogen; a conical metal-made fixing ring that has an inner surface with an upwardly increasing horizontal cross-sectional area for receiving the conical electrode inserted therein; a unit support member for supporting the fixing ring; fitting flanges arranged at mutually opposite surfaces of the fixing ring and the unit support member; gaskets made of metal or a mineral-based material and interposed between the fixing ring and the unit support member; and fastening members for separably fastening the fitting flanges.
 10. The high temperature steam electrolyzing device according to claim 9, wherein the oxygen electrode is disk-shaped, and the annular fixing ring for receiving the solid oxide electrolyte inserted therein and the unit support member are connected by way of screw sections.
 11. The high temperature steam electrolyzing device according to claim 9, wherein the unit support member has a hydrogen electrode feed layer for feeding electricity to the hydrogen electrode of the electrolyzing cell section, an oxygen electrode collection layer for collecting electricity from the oxygen electrode and an insulation layer for insulating the hydrogen electrode feed layer and the oxygen electrode collection layer, and the fixing ring for receiving the oxygen electrode inserted therein and the oxygen electrode feed layer of the unit support member are connected by way of a weld section.
 12. The high temperature steam electrolyzing device according to claim 9, wherein the fixing ring for receiving the oxygen electrode inserted therein and the unit support member are disposed face to face by way of an annular gap.
 13. A high temperature steam electrolyzing device comprising: an electrolyzing cell section that includes a hydrogen electrode and an oxygen electrode arranged at mutually opposite sides of a solid oxide electrolyte operating as intermediate layer and electrolyzes steam to generate hydrogen; a porous metal-made support member for supporting lower surface of the hydrogen electrode of the electrolyzing cell section; a metal-made fixing ring arranged outside the porous metal-made support member and connected to end surface of the porous metal-made support member by way of a weld section; and a unit support member for support end section of the metal-made fixing ring.
 14. The high temperature steam electrolyzing device according to claim 13, wherein the device includes fitting flanges arranged at mutually opposite surfaces of the metal-made fixing ring and the unit support member, gaskets made of metal or a mineral-based material and interposed between the electrolyzing cell section and the fitting flanges and between the unit support member and the fitting flanges, and fastening members for separably fastening the fitting flanges, and the metal-made fixing ring is annular and the fixing ring and the unit support member are connected by way of a screw section.
 15. The high temperature steam electrolyzing device according to claim 13, wherein: the unit support member has a hydrogen electrode feed layer for feeding electricity to the hydrogen electrode of the electrolyzing cell section, an oxygen electrode collection layer for collecting electricity from the oxygen electrode, and an insulation layer for insulating the hydrogen electrode feed layer and the oxygen electrode collection layer; and the metal-made fixing ring and the hydrogen electrode feed layer of the unit support member are connected by way of a weld section.
 16. The high temperature steam electrolyzing device according to claim 13, further comprising fitting flanges arranged at mutually opposite surfaces of the metal-made fixing ring and the unit support member, gaskets made of metal or a mineral-based material and interposed between the electrolyzing cell section and the fitting flanges and between the unit support member and the fitting flanges, and fastening members for separably fastening the fitting flanges, wherein the metal-made fixing ring and the unit support member are disposed face to face by way of an annular gap. 